I have to agree with the previous posts...
I don't think that your quilt sandwich is feeding evenly...
It is either being held down by weight or not fully supported that it can evenly feed through your machine.
Try putting something on the left side of your machine...either move your machine more to the right of the table or use a chair back or something to hold it, the weight...
And you will probably want to slow down...
I piece fast and machine quilt slow...so I can "feel" the fabric if there are any lumps or irregularities coming up with my sandwich...
Hope this helps.
K